1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
jarptica [38.1K]
3 years ago
14

How many elements are there

Chemistry
1 answer:
yawa3891 [41]3 years ago
4 0
There are 118 known elements
You might be interested in
It has been suggested that hydrogen gas obtained by the decomposition of water might be a substitute for natural gas (principall
Aleks [24]

Answer:

Hydrogen: -141 kJ/g

Methane: -55kJ/g

The energy released per gram of hydrogen in its combustion is higher than the energy released per gram of methane in its combustion.

Explanation:

According to the law of conservation of the energy, the sum of the heat released by the combustion and the heat absorbed by the bomb calorimeter is zero.

Qc + Qb = 0

Qc = -Qb  [1]

We can calculate the heat absorbed by the bomb calorimeter using the following expression.

Q = C . ΔT

where,

C is the heat capacity

ΔT is the change in the temperature

<h3>Hydrogen</h3>

Qc = -Qb = -C . ΔT = -(11.3 kJ/°C) . (14.3°C) = -162 kJ

The heat released per gram of hydrogen is:

\frac{-162kJ}{1.15g} =-141 kJ/g

<h3>Methane</h3>

Qc = -Qb = -C . ΔT = -(11.3 kJ/°C) . (7.3°C) = -82 kJ

The heat released per gram of methane is:

\frac{-82kJ}{1.50g} =-55kJ/g

3 0
3 years ago
In Humans, the liquid waste
Kay [80]
The answer is b (bladder)
8 0
3 years ago
Which analogy best represents a supersaturated solution? an empty elevator that has a maximum load of 20 people a single person
Karo-lina-s [1.5K]
25 people in an elevator that has a maximum load of 20 people
8 0
3 years ago
Read 2 more answers
What is the value of the activation energy of the uncatalyzed reaction?
Lubov Fominskaja [6]
The value of the activation energy of an uncatalyzed reaction is greater than that of a catalyzed reaction. As we know, a catalyst provides an alternative path for the reaction to happen at a faster rate. So, for a catalyzed reactio, activation energy is lesser than the original path.
6 0
3 years ago
What would be the volume of 0.500 mole of an ideal gas at a temperature of 273.15 Kelvins and 1 atm?
uysha [10]

Answer:

V = 11.21 L

Explanation:

Given data:

Volume of helium = ?

Number of moles = 0.500 mol

Temperature = 273.15 K

Pressure of gas = 1 atm

Solution:

Formula:

PV = nRT

R = general gas constant = 0.0821 atm.L/ mol.K

V = nRT/P

V = 0.500 mol ×  0.0821 atm.L/ mol.K  × 273.15 K / 1 atm

V = 11.21 L / 1

V = 11.21 L

8 0
3 years ago
Other questions:
  • Atoms clump together
    6·1 answer
  • The half-life of plutonium-239 is 24300. If a nuclear bomb released 8kg of this isotope, how many years would pass before the am
    10·1 answer
  • Which of the following is most likely a solid that is not a good conductor of electricity? A. Nickel B. Sodium C. Silicon D. Flu
    6·1 answer
  • List the number of each type of atom on the left side of the equation 2C6H14(l)+19O2(g)→12CO2(g)+14H2O(g) Enter your answers sep
    14·1 answer
  • If you combined neon argon and helium together what would you expect to happen
    15·1 answer
  • What type of chemical reaction is NaHCO3=Na2CO3+H2O+CO2​
    6·1 answer
  • What is the number of copper atom in one naira coin which weight is 7.3g a sum of the material is 86%
    5·1 answer
  • Which of the following is not a natural
    12·2 answers
  • What is the substrate of the enzyme pepsin
    10·1 answer
  • Exhaling CO2 (Carbon Dioxide) is an example of what?
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!